This study investigates whether a type of psychotherapy called Behavioral Activation (BA) is as effective as antidepressant medication in the treatment of adolescents diagnosed with depression. In this study, BA is compared to fluoxetine, which is known to help treat depressive symptoms in this population. BA has been shown to be efficacious in reducing depression in adolescents, but it is not yet known how it compares to another leading treatment for depression in this age group. Thus, this study's primary goal is to see how BA compares to fluoxetine.